IL-10 & PD-1 Modulation to Reduce CMV Disease Incidence in Solid Organ Recipients

描述（由申请人提供）：实体器官移植（SOT）受者的巨细胞病毒感染严重影响该治疗的恢复过程和成功率。发病率的增加反映了感染的严重程度，可导致移植物丢失和患者死亡，这与巨细胞病毒疾病有关。尽管抗病毒治疗方案取得了重大进展，但在停止抗病毒预防治疗后，SOT接受者仍有发展为晚期巨细胞病毒疾病的风险。预防危及生命的巨细胞病毒疾病的替代方法是管理来自巨细胞病毒阳性供体（D+）的SOT的巨细胞病毒阴性受体（R-）的关键优先事项，因为约30%的巨细胞病毒原发感染发展为临床疾病。我们的长期目标是确定D+/R-受体原发性抗巨细胞病毒反应的质量和数量，以便为易患巨细胞病毒疾病风险增加的患者制定预防和治疗策略。我们已经报道，在D+/R-肝移植（Tx）患者中，对CMV病毒血症升高的反应中获得t细胞溶解功能和IFN-3的产生是保护性免疫反应的不可靠指标。相反，CMV特异性t细胞上的阴性免疫调节程序性死亡(PD)-1受体的高水平可预测CMV疾病。我们的初步研究表明，在CMV症状性D+/R-患者中，抑制性白细胞介素(IL)- 10的产生与PD-1的表达增加平行增加。此外，表达高PD-1水平的功能性cmv特异性t细胞表现出明显的增殖缺陷。该提议的中心假设是，抑制性免疫信号水平升高表明免疫损伤状态，这先于巨细胞病毒疾病的发展：免疫抑制环境的逆转应该恢复保护性巨细胞病毒免疫。本提案的目的是表征PD-1和IL-10表达的tx后动力学，这将为这些阴性免疫调节剂的阻断策略奠定基础。一组35例肝、肺和心脏D+/R-患者，其中约12例预计会发展为巨细胞病毒疾病，将在Tx后6个月内每两周监测一次巨细胞病毒疾病、巨细胞病毒特异性临床参数和激活标志物PD-1和IL-10。CMV特异性t细胞的免疫监测将包括用CMV病毒裂解液和6个肽库刺激后的多参数流式细胞术分析，包括免疫优势和经常识别的CMV抗原（pp65, IE1, IE2, US3, US32, UL99）。这些纵向数据将有助于确定原发性巨细胞病毒感染的SOT受体的免疫状态或免疫失调程度。接下来，将在巨细胞病毒患者中确定抗pd -1和/或IL-10抗体在恢复巨细胞病毒特异性t细胞增殖能力方面的影响。这些结果将为设计抗体阻断平台的临床试验提供信息，用于高风险SOT受体的临床管理，和/或提高抗巨细胞病毒疫苗接种策略的有效性。这项R21奖励将为基于抗体的临床试验提供理论依据，以减少SOT受者巨细胞病毒疾病发病率和/或影响。公共卫生相关性：拟议的研究旨在降低接受实体器官移植（SOT）患者的死亡率和改善临床管理。由于抗排斥反应和免疫抑制治疗，SOT受者对几种病原体高度敏感，其中巨细胞病毒（CMV）是影响康复的最重要的临床感染。在我们的项目中，我们将描述导致危及生命的巨细胞病毒并发症的免疫功能障碍，目的是制定预防或治疗策略，以恢复高危SOT患者的这种缺陷。

DESCRIPTION (provided by applicant): CMV infection in solid organ transplant (SOT) recipients strongly impacts the course of recovery and success rate of this therapy. Increased morbidity that reflects the severity of infection, which can lead to graft loss and patient death, is associated with CMV disease. Despite significant advances in antiviral regimens, SOT recipients remain at risk for developing late CMV disease, after discontinuation of antiviral prophylaxis. Alternative approaches to preventing life-threatening CMV disease are a critical priority in the management of CMV-negative recipients (R-) of SOT from a CMV-positive donor (D+), since CMV primary infection progresses to clinical disease in ~30% of D+/R-. Our long term goal is to characterize quality and quantity of primary anti- CMV response in D+/R- recipients, for developing preventive and therapeutic strategies for patients susceptible to increased risk of CMV disease. We have reported that the acquisition of T-cell lytic function and IFN-3 production in response to rising CMV viraemia is an unreliable indicator of a protective immune response, in D+/R- liver transplant (Tx) patients. In contrast, high levels of the negative immune-modulator programmed death (PD)-1 receptor on CMV-specific T-cells are predictive of CMV disease. Our Preliminary Studies indicate that in CMV symptomatic D+/R- patients there is a parallel increased production of suppressive interleukin (IL)- 10 with increased expression of PD-1. Additionally, functional CMV-specific T-cells, expressing high PD-1 levels, show a marked deficit of proliferation. The central hypothesis of this proposal is that elevated levels of inhibitory immune-signaling indicate a state of immune impairment, which precedes development of CMV disease: reversal of the immunosuppressive environment should restore protective CMV immunity. The objective of this proposal is to characterize the post-Tx kinetics of PD-1 and IL-10 expression, which will lay the ground work for a blocking strategy of these negative immuno-modulators. A cohort of 35 liver, lung and heart D+/R- patients, in which ~12 are expected to develop CMV disease, will be monitored biweekly within 6 months after Tx, for CMV disease, CMV-specific clinical parameters and activation markers, PD-1 and IL-10. Immune- monitoring of CMV-specific T-cells will include multi-parameter flow cytometry analyses following stimulation with CMV viral lysate and 6 peptide libraries, encompassing immunodominant and frequently recognized CMV antigens (pp65, IE1, IE2, US3, US32, UL99). These longitudinal data will help identify the immune status or degree of immune-dysregulation of SOT recipients with primary CMV infection. Next, the impact of anti-PD-1 and/or IL-10 antibodies in restoring the proliferative capacity of CMV-specific T-cells will be determined in patients with CMV disease. These latter results will prove informative to design a clinical trial of an antibody blockade platform, to be used in the clinical management of high risk SOT recipients, and/or to increase the efficacy of anti-CMV vaccination strategies. This R21 award will provide the rationale for antibody-based clinical trials to reduce the incidence and/or impact of CMV disease incidence in SOT recipients. PUBLIC HEALTH RELEVANCE: The proposed studies are aimed to reduce the mortality and improve the clinical management of patients that have received solid organ transplantation (SOT). Due to anti-rejection and immunosuppressive treatments, SOT recipients become highly susceptible to several pathogens, among which cytomegalovirus (CMV) is the most significant clinical infection impairing recovery. In our project, we will characterize the immune dysfunctions that lead to life-threatening CMV complications, with the purpose of formulating preventive or therapeutic strategies to revert such defects in high risk SOT patients.